1. Field of the Invention
The present invention relates to a panel for automobiles, and in particular to a panel made of glass or transparent plastic material.
2. Description of the Prior Art
A panel of this type is commonly known as a sun roof, and for preference replaces that part of the metal roof above the front seats.
The panel is made of glass or other transparent material and has a light and energy transmission factor not exceeding 25% of the incident energy, so as to prevent unpleasant irradiation of the inside of the vehicle. That is, the light and energy transmission factor is a measure of the amount of light or energy directly transmitted through the glass.
In order to obtain the above light and energy transmission factor, sun roofs are generally made of glass having a thickness of between 3 and 5 mm, provided with suitable silk-screen coatings and/or thin reflective layers.
These sun roofs make it possible to increase the comfort level inside automobiles, particularly during the hotter months of the year, thanks to the improved circulation of air within the interior of the vehicle.
However, there are certain problems during the colder months of the year, when the high level of humidity and the cold outside cause mist to form on the inner surface of the sun roof. Furthermore, the difference in temperature between the inside and the outside of the vehicle generates an unpleasant coldness at the level of the occupants' heads.
In order to overcome the above problems, sliding false roofs made of the same materials as the inside upholstery are at present installed in the roofs of automobiles, which act as a screen separating the transparent sun roof from the rest of the interior during the colder months.
The use of such false roofs is sometimes advisable even during summer months, in particular in the presence of extremely strong sunshine.
It can be appreciated that the production and assembly of these false roofs gives rise to additional manufacturing costs.